This invention relates to a precompounded polychloroprene (neoprene) formulation that bonds effectively to fluoroelastomers, fluoroplastics, polypropylene, polyvinylchloride, chlorinated polyethylene, and acrylonitrile polymers when vulcanized in contact with these materials. The invention further relates to incorporating this material as a bonding layer into an elastomeric article, for instance a hose, in which one layer (i.e. tube or cover) is made of one of the above listed materials, and it is not readily bondable to the other layer (i.e. reinforcement layer, cover, tube). The bonding layer then forms a strong bond to both layers it is in contact with when vulcanized, as when used as an interlayer between a tube and cover of dissimilar materials not readily bondable to each other.
In the past, organic acceleration systems such as: ethylene thiourea; salicyclic acid, tetramethylthiuram monosulfide-sulfur; diphenylguanidine-sulfur; diorthotolyguanidine salt of dicatecholborate; and tetramethylthiuram monosulfide-sulfur-diorthotolyguanidine were commonly used to vulcanize polychloroprene. Organic accelerators are generally used to aid in controlling the time and temperature required for vulcanization and thereby improve the properties of the vulcanizate. To Applicant's knowledge, the accelerator has not been used heretofor as a facilitator to promote bonding between two layers made of unlike materials when vulcanized in contact with each other.
In hose manufacture, a manually applied adhesive has been previously used to bond the tube layer to the cover upon curing. However, the application of the adhesive adds to the cost of manufacture and complicates processing.
Prior art incorporating a bonding layer or an elastomeric interlayer in hose manufacture include U.S. Pat. Nos. 3,651,176 to Usamoto et al, 3,660,224 to Cau et al, 3,712,360 to Torti et al, 3,994,453 to Chudgar et al, and 4,096,888 to Stefano et al.
It is a primary object of the invention to provide a compounded polychloroprene formulation that effectively bonds to fluoroelastomers, fluoroplastics, polypropylene, polyvinylchloride, chlorinated polyethylene, and acrylonitrile polymers when vulcanized in contact with these materials. A further object is to provide a hose incorporating this polychloroprene formulation as an interlayer between the tube and cover, which bonds to both layers it is in contact with upon vulcanization of the hose, using a standard vulcanization process and without the need for separate bonding layers.